Described herein are toner processes, and more specifically, aggregation and coalescence processes, for the preparation of toner compositions. More particularly, described are methods of reacting toner components during the fusing process to provide a more permanent image and to improve document offset and crease properties.
Document offset refers to how well the toner remains on the image recording medium, such as paper or a package, after the image has been printed. This is particularly important when the printed items are stacked upon each other. Crease property refers to how well an image avoids cracking when the image is folded or creased.
Existing toners often lack the ability to permanently remain on a medium after printing. It's especially important for an image printed on a material to be used in packaging to be permanent as packages are frequently bent and twisted.
In forming an image on a package or on a label to be attached to a package, the image is printed onto the medium. Once the image is printed, the medium with the image thereon is heated to fuse the image onto the recording medium, e.g., cardboard box or label. Once an image is printed, an overcoat varnish may be placed over the image. The varnish may be crosslinked to increase the molecular weight of the varnish and make the varnish seal more permanent.
For forming the image, toners such as emulsion aggregation toners may be used. Such a toner is prepared by the well known emulsion aggregation technique. This technique or process for the preparation of toner is illustrated in a number of Xerox patents, the disclosures of which are totally incorporated herein by reference, such as U.S. Pat. No. 5,290,654, U.S. Pat. No. 5,278,020, U.S. Pat. No. 5,308,734, U.S. Pat. No. 5,370,963, U.S. Pat. No. 5,344,738, U.S. Pat. No. 5,403,693, U.S. Pat. No. 5,418,108, U.S. Pat. No. 5,364,729, and U.S. Pat. No. 5,346,797. Also of interest may be U.S. Pat. Nos. 5,348,832; 5,405,728; 5,366,841; 5,496,676; 5,527,658; 5,585,215; 5,650,255; 5,650,256; 5,501,935; 5,723,253; 5,744,520; 5,763,133; 5,766,818; 5,747,215; 5,827,633; 5,853,944; 5,804,349; 5,840,462; 5,869,215; 5,910,387; 5,919,595; 5,916,725; 5,902,710; 5,863,698, 5,925,488; 5,977,210 and 5,858,601. The appropriate components and process parameters of the above Xerox patents may be selected for use in embodiments described herein.